CentOS 7上安装Kubernetes集群部署Docker

1.操作系统详情
需要三台主机，都最小化安装CentOS7.3,并update到最新
cat /etc/RedHat-release
CentOS Linux release 7.3.1611 (Core)
角色主机名IP
Master master192.168.1.14
node1 slave-1192.168.1.15
node2slave-2192.168.1.16

2.在每台主机上关闭firewalld改用iptables
输入以下命令，关闭firewalld
systemctl stop firewalld.service #停止firewall
systemctl disable firewalld.service #禁止firewall开机启动
然后安装iptables并启用
yum install -y iptables-services #安装
systemctl start iptables.service #最后重启防火墙使配置生效
systemctl enable iptables.service #设置防火墙开机启动

3.安装ntp服务
yum install -y ntp
systemctl start ntpd
systemctl enable ntpd

二、安装配置
注：kubernetes，etcd等已经进去centos epel源，可以直接yum安装（需要安装epel-release）

1.安装Kubernetes Master

使用以下命令安装kubernetes 和 etcd
# yum install -y kubernetes etcd
编辑/etc/etcd/etcd.conf 使etcd监听所有的ip地址，确保下列行没有注释，并修改为下面的值
vim /etc/etcd/etcd.conf
# [member]
ETCD_NAME=default
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_INITIAL_CLUSTER="default=http://192.168.1.14:2380"
#[cluster]
ETCD_ADVERTISE_CLIENT_URLS="http://192.168.1.14:2379"
编辑Kubernetes API server的配置文件 /etc/kubernetes/apiserver，确保下列行没有被注释，并为下列的值
vim /etc/kubernetes/apiserver
###
# kubernetes system config
#
# The following values are used to configure the kube-apiserver
#
# The address on the local server to listen to.
KUBE_API_ADDRESS="--address=0.0.0.0"
# The port on the local server to listen on.
KUBE_API_PORT="--port=8080"
# Port minions listen on
KUBELET_PORT="--kubelet_port=10250"
# Comma separated list of nodes in the etcd cluster
KUBE_ETCD_SERVERS="--etcd_servers=http://192.168.1.14:2379"
# Address range to use for services
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
# default admission control policies
KUBE_ADMISSION_CONTROL="--admission_control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota"
# Add your own!
KUBE_API_ARGS=""
启动etcd,kube-apiserver,kube-controller-manager and kube-scheduler服务，并设置开机自启
vim /script/kubenetes_service.sh
for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler; do
systemctl restart $SERVICES
systemctl enable $SERVICES
systemctl status $SERVICES
done
sh /script/kubenetes_service.sh
在etcd中定义flannel network的配置，这些配置会被flannel service下发到nodes:
etcdctl mk /centos.com/network/config '{"Network":"172.17.0.0/16"}'
添加iptables规则，允许相应的端口
iptables -I INPUT -p tcp --dport 2379 -j ACCEPT
iptables -I INPUT -p tcp --dport 10250 -j ACCEPT
iptables -I INPUT -p tcp --dport 8080 -j ACCEPT
iptables-save
或者写入iptables配置文件 /etc/sysconfig/iptables
查看节点信息（我们还没有配置节点信息，所以这里应该为空）
# kubectl get nodes
NAME LABELS STATUS

2. 安装Kubernetes Minions (Nodes)
注：下面这些步骤应该在minion1和minions2上执行（也可以添加更多的minions）
使用yum安装kubernetes 和 flannel
# yum install -y flannel kubernetes
为flannel service配置etcd服务器，编辑/etc/sysconfig/flanneld文件中的下列行以连接到master
# vim /etc/sysconfig/flanneld
FLANNEL_ETCD="http://192.168.1.14:2379" #改为etcd服务器的ip
FLANNEL_ETCD_PREFIX="/centos.com/network"
编辑/etc/kubernetes/config 中kubernetes的默认配置，确保KUBE_MASTER的值是连接到Kubernetes master API server：
# vim /etc/kubernetes/config
KUBE_MASTER="--master=http://192.168.1.14:8080"
编辑/etc/kubernetes/kubelet 如下行：
node1:
# vim /etc/kubernetes/kubelet
KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname_override=192.168.1.15"
KUBELET_API_SERVER="--api_servers=http://192.168.1.14:8080"
KUBELET_ARGS=""
node2:
# vim /etc/kubernetes/kubelet
KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname_override=192.168.1.16"
KUBELET_API_SERVER="--api_servers=http://192.168.1.14:8080"
KUBELET_ARGS=""
启动kube-proxy,kubelet,docker 和 flanneld services服务，并设置开机自启
for SERVICES in kube-proxy kubelet docker flanneld; do
systemctl restart $SERVICES
systemctl enable $SERVICES
systemctl status $SERVICES
done
在每个minion节点，你应当注意到你有两块新的网卡docker0 和 flannel0。你应该得到不同的ip地址范围在flannel0上，就像下面这样：
node1:
# ip a | grep flannel | grep inet
inet 172.17.29.0/16 scope global flannel0
node2:
# ip a | grep flannel | grep inet
inet 172.17.37.0/16 scope global flannel0
添加iptables规则：
iptables -I INPUT -p tcp --dport 2379 -j ACCEPT
iptables -I INPUT -p tcp --dport 10250 -j ACCEPT
iptables -I INPUT -p tcp --dport 8080 -j ACCEPT
现在登陆kubernetes master节点验证minions的节点状态：
# kubectl get nodes
NAME LABELS STATUS
192.168.1.15 kubernetes.io/hostname=192.168.1.15 Ready
192.168.1.16 kubernetes.io/hostname=192.168.1.16 Ready
至此，kubernetes集群已经配置并运行了，我们可以继续下面的步骤。

三、创建 Pods (Containers)
为了创建一个pod，我们需要在kubernetes master上面定义一个yaml 或者 json配置文件。然后使用kubectl命令创建pod
# mkdir -p /k8s/pods
# cd /k8s/pods/
# vim nginx.yaml
在nginx.yaml里面增加如下内容：
apiVersion: v1
kind: Pod
metadata:
name: nginx
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
创建pod:
# kubectl create -f nginx.yaml
此时有如下报错：
Error from server: error when creating "nginx.yaml": Pod "nginx" is forbidden: no API token found for service account default/default,retry after the token is automatically created and added to the service account
解决办法是编辑/etc/kubernetes/apiserver 去除 KUBE_ADMISSION_CONTROL中的SecurityContextDeny,ServiceAccount，并重启kube-apiserver.service服务：
#vim /etc/kubernetes/apiserver
KUBE_ADMISSION_CONTROL="--admission_control=NamespaceLifecycle,ResourceQuota"
#systemctl restart kube-apiserver.service
之后重新创建pod:
# kubectl create -f nginx.yaml
pods/nginx
查看pod:
# kubectl get pod nginx
NAME READY STATUS RESTARTS AGE
nginx 0/1 Image: nginx is not ready on the node 0 34s
这里STATUS一直是这个，创建不成功，下面排错。通过查看pod的描述发现如下错误：
# kubectl describe pod nginx
Wed,28 Oct 2015 10:25:30 +0800 Wed,28 Oct 2015 10:25:30 +0800 1 {kubelet 192.168.1.16} implicitly required container POD pulled Successfully pulled Pod container image "gcr.io/google_containers/pause:0.8.0"
Wed,28 Oct 2015 10:25:30 +0800 1 {kubelet 192.168.1.16} implicitly required container POD failed Failed to create docker container with error: no such image
Wed,28 Oct 2015 10:25:30 +0800 1 {kubelet 192.168.1.16} failedSync Error syncing pod,skipping: no such image
Wed,28 Oct 2015 10:27:30 +0800 Wed,28 Oct 2015 10:29:30 +0800 2 {kubelet 192.168.1.16} implicitly required container POD failed Failed to pull image "gcr.io/google_containers/pause:0.8.0": image pull failed for gcr.io/google_containers/pause:0.8.0,this may be because there are no credentials on this request. details: (API error (500): invalid registry endpoint "http://gcr.io/v0/". HTTPS attempt: unable to ping registry endpoint https://gcr.io/v0/
v2 ping attempt failed with error: Get https://gcr.io/v2/: dial tcp 173.194.72.82:443: i/o timeout
这里可能会遇到pod状态一直处于Penning的问题，此时可以通过kubectl describe pods/pod-name来查看pod信息，如果没有出错信息，那么Minion一直处于下载镜像中，下载好之后pod即会成功启动。
从网上找到 pause:0.8.0 的镜像，然后再每个node上导入镜像：
请在境外docker服务器执行 docker pull 命令下载镜像
gcr.io/google_containers/pause:latestgcr.io/google_containers/pause:1.0gcr.io/google_containers/pause:0.8.0
再用导出镜像
docker save -o pause.tar gcr.io/google_containers/pausegzip pause.tar
最后把这个包放到 kubernetes 环境所有的 docker 服务器上
docker load -i pause.tar.gz
在执行以下命令即可成功创建pod
[root@master ~]#kubectl create -f nginx.yamlpods/nginx
查看pod
[root@master ~]# kubectl get pod nginxNAME READY STATUS RESTARTS AGEnginx 1/1 Running 0 2min
前往nodes节点上查看docker images
[root@slave1 ~]# docker imagesREPOSITORY TAG

更多Docker相关教程见以下内容：

Docker安装应用(CentOS 6.5_x64)http://www.linuxidc.com/Linux/2014-07/104595.htm

Ubuntu14.04安装Dockerhttp://www.linuxidc.com/linux/2014-08/105656.htm

Ubuntu使用VNC运行基于Docker的桌面系统http://www.linuxidc.com/Linux/2015-08/121170.htm

阿里云CentOS 6.5 模板上安装 Dockerhttp://www.linuxidc.com/Linux/2014-11/109107.htm

Ubuntu 15.04下安装Dockerhttp://www.linuxidc.com/Linux/2015-07/120444.htm

在Ubuntu Trusty 14.04 (LTS) (64-bit)安装Dockerhttp://www.linuxidc.com/Linux/2014-10/108184.htm

在 Ubuntu 15.04 上如何安装Docker及基本用法http://www.linuxidc.com/Linux/2015-09/122885.htm

Ubuntu 16.04上Docker使用手记http://www.linuxidc.com/Linux/2016-12/138490.htm

Docker 的详细介绍：请点这里
Docker 的下载地址：请点这里

本文永久更新链接地址：http://www.linuxidc.com/Linux/2017-04/142676.htm